Pick having limited angular movement, opposed directional cutting faces, and trunnion mounting therefor



. N V- 26, 1958 G. R. o. PENTITH ETAL 3,413,036

PICK HAVING LIMITED ANGULAR MOVEMENT, OPPOSED DIRECTIONAL CUTTING FACES, AND TRUNNION MOUNTING THEREFOR Filed Nov. 16, 1966 5 M ,1 gm

United States Patent 0 3,413,036 PICK HAVING LIMITED ANGULAR MOVEMENT, OPPOSED DIRECTIONAL CUTTING FACES, AND TRUNNION MOUNTING THEREFOR Gerald R. O. Pentith, Aycliffe, near Darlington, and Frederick Webster, Sheffield, England, assignors, by mesne assignments, to Mining Progress Inc., Highland Mills, N.Y., a corporation of New York Filed Nov. 16, 1966, Ser. No. 594,934 Claims priority, application Great Britain, Nov. 20, 1965, 49,387/ 65 8 Claims. (Cl. 29985) ABSTRACT OF THE DISCLOSURE Pick and pick-mounting combination for use in a mineral machine including a pick having a head with two oppositely directed cutting faces and a shank with a transverse hole in a direction parallel to the face widths, a trunnion block member forming one part of the mounting and having a central portion provided with a transverse socket to receive the shank, the block \member having a hole intersected by the socket to register with the shank hole, a pin extending through the registering holes locating and securing the shank in the socket, the block member having coaxial trunnions extending in opposite directions at right angles to the lengthwise direction of the socket, for example with each trunnion having a pair of diametrically opposed recesses, and a journal member forming a second part of the mounting and having two side portions, a journal in each side portion for one of the trunnions, for example with bearing bushes in the journals, and for example with stop means in operative association with the trunnion recesses, with play between the stop means and the respective recesses, to provide two positions of rest for the block member, whereby to permit limited angular movement of the block member and a pick secured in its socketed position with its operative end protmding beyond the journal member side portions.

This invention relates to picks for shearer discs or drums of machines for mining coal and other minerals, the objects of the invention being to provide a two-faced pick so mounted that it automatically reverses to effective cutting position on reversal of the disc or drum on which it is mounted, as when the machine is called on to cut first in one direction over a face and then in the opposite direction, when the disc or drum can, by being reversed, more effectively attack the mineral to be detached and/ or remove from its own vicinity mineral that it has already detached. It is also desirable that the part of the pick bearing the cutting face that is operative in one direction of cutting shall not be impaired by contact with the mineral surface in the reversed cutting or interfere with the effective application to the mineral surface of the cutting face that is then operative.

With the above features in mind, the invention provides a pick that is movable in its mounting from one position in which it is firmly supported, for effective cutting by one of its faces in one direction, to another position in which the like support for effective cutting by its other face is obtained, there being provision made against interference to the assumption of the pick of each of its operative positions by the presence of dust and debris inevitably produced during the operation of the pick.

Accordingly, a pick and pick-mounting combination for use in a mineral mining machine comprises, according to the invention, a pick having a head with two oppositely directed cutting faces and a shank formed with a trans- "ice verse hole in a direction parallel to the face widths, a trunnion block member constituting one part of the mounting and having a central portion formed with a transverse socket to receive the pick shank and with a hole intersected by the socket to register with the hole in the pick shank, togther with a pin to locate and secure the shank in the socket by passing through the registering holes, the block member having coaxial trunnions extending in opposite directions at right angles to the lengthwise direction of the socket, and a journal member constituting a second part of the mounting, the member having two side portions each journalled for one of the trunnions of the block member, there being within the journals stop means in operative association with recesses formed in the trunnions, with play between the stop means and the respective recesses to provide limited angular movement of the trunnion block member and a pick secured in its socketed position with its operative end protruding beyond the side pieces of the journal member.

With the mounting member secured to a cutting disc or drum so that the space between the side members (occupied by the central portion of the journal member) is orientated in the general direction of movementin either direction-of the mounting member when the disc or drum is in operation, a pick secured in the socket presents its two cutting faces in opposite directions with respect to this direction of movement. One face is therefore the front face and is brought into contact with the mineral to be cut, and by such contact it is forced backwards, with pivoting of the journal member on its trunnions until one stoplimit is reached. The pick, generally supported by the trunnions journalled in the side members, is now firmly supported by the stops, so that cutting is effected by its front face. On reversal of the direction of rotation of the disc or drum, the other face of the pick becomes the front face, and the pick is similarly rocked to the other stoplimit to bring that face into its firmly supported cutting position.

Preferably, the central portion has the circular section of bar material from which the trunnions are turned, and this circular portion and the pick supported in its socket are able to swing freely between the side portions, without interference from dust and debris. Also, the trunnions may rotate in bearing bushes in the journals, e.g., of resinbonded fabric-reinforced material that serves as a seal against the ingress of dust to the stop pins.

This enables the pick to be of simple construction, with cutting faces (preferably formed as usual from inserted tips of tungsten carbide or like hard metal) having correct front rake and end rake when the pick is rocked to each of its cutting positions. The end face of the tip not in use then lies clear of the surface that is being attacked by the tip in use.

The stops for limiting the rocking may simply consist of strong pins held in holes in the side portions diametrically of the trunnion journals and passing through clearance holes diametrically of the trunnions, the clearance providing for the desired swinging before the pick becomes solidly supported by contact of the sides'of the clearance holes (or of clearance bushes inserted in the holes) with the pins.

The invention includes not only the combination of the pick and mounting as above described, but the mounting itself and picks for use with the mounting.

The invention will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a part-sectional front elevation of a pick and pick mounting, with the pick shown midway between its two operative positions; and

FIGURE 2 is a part-sectional side elevation on the line 3 22 of FIGURE 1, the operative positions of the pick being indicated in broken line.

A pick 1 has a head 2 with two oppositely directed tipped cutting faces 3, and a shank 4 having two spaced transverse holes 5 parallel to the face widths. The shank 4 fits in a socket 6 in the central portion 7 of a trunnion block 8 of circular section formed from bar material from which trunnions 9 are turned. The trunnion block is formed with two longitudinal holes 10 which intersect the socket 6 and register with the holes 5 in the shank, pins 11 passing through the holes 10, 5 to secure the shank 4 in the socket 6, the spring pins 12 at each end of each pin securing the pins to the trunnion block.

A journal member 13 is formed as a single casting and has two side portions 14 connected by webs 15 and a bottom web 16, the inner faces of the webs 15 having an arcuate form to fit closely the central portion 7 of the trunnion block 8 and the bottom web being spaced from the central portion 7. Each side portion 14 is journalled at 17 to receive one trunnion 9, the journals having a diameter' equal to that of the central portion 7 of the trunnion block 8, a bearing bush 18 of resin-bonded fabricreinforced material secured to each trunnion filling the annular space between the trunnion and its journal.

Through each trunnion 9 there is a diametrically-dis posed hole 19 with its central axis parallel to the transverse axis of the pick 1. Each end of the hole 19 is enlarged by upper and lower outwardly divergent arcuate portions 20 forming bearing surfaces 21 (FIGURE 2). Each hole 19 receives a pin 22 having a radius equal to that of the arcuate upper and lower divergent extensions 20 to the hole 19, the pin passing through diametrally opposite holes 23, 24 (FIGURE 2) through the side portions 14 and the bush 18, respectively, each pin being secured by spring pins 25.

Thus, with the journal member '13 secured to a shearer disc or drum, e.g., by welding the bottom web to the disc or drum, rotation of the disc or drum in one direction causes the pick to assume the position indicated at X in FIGURE Z, on contact with the face to be cut. In this position,"the pick is correctly set for negative rake cutting, the trunnion block 8 having pivoted until the upper bearing surface 21 at one end of each hole 19 and the lower bearing surface at the other end have contacted the pins 22 to firmly support the pick in its operative position, and prevent sideways-floating of the pick during the cutting operation. On reversal of the disc or drum, contact by the pick with the face causes it to assume the position indicated at Y, when again it is correctly set for negative rake cutting, the other bearing surfaces having been brought into contact with the pins 22. Swivelling of the pick about the axis of the trunnions to one or other of its operative positions causes the part central portion 7 immediately adjacent the pick shank to close the bottom of the space between the side portions 14 above the side webs 15, so that no crevice or gap between parts is provided into which debris can jam to hinder the swivelling of the pick or prevent com pletely the pick from assuming its correct cutting position. In addition, dust and debris is prevented from reaching the bearing surfaces 21 by the bush 18.

When the pick cutting faces have worn or when the pick has been damaged, it can easily be replaced by simply removing the pins 11 and pulling the pick out of the socket. If the pick is stuck in the socket, then a drift can be inserted in the space between one web 15 and the bottom web 16 of the journal member '13 to force the pick out of the socket. In the unlikely event of damage or wear to the trunnion block, this can also be readily replaced by removing the pins 22 and pushing the trunnion block out of the journal member, and replacing it with a new block, the pins'22 then being replaced.

In an alternative construction not shown, the journal member 13 is formed in two halves, without webs intermediate the top and bottom, the two halves being welded together at their bottom webs around the trunnion block cal which could then have a central section of rectangular cross-section formed from bar material in which the trunnions are turned. There being no intemediate webs, there is nothing which can cooperate with the central section of the block to form a crevice into which debris can jam.

What we claim is:

1. A pick and pick-mounting combination for use in a mineral mining machine comprising a pick, a head on the pick, two oppositely directed cutting faces on the head, a pick shank having a transverse hole in a direction parallel to the face widths, a trunnion block member constituting one part of the mounting and having a central portion with a transverse socket to receive the pick shank, the trunnion block member having a hole intersected by the socket to register with the hole in the shank, a pin extending through the registering holes locating and securing the shank in the socket, the block member having coaxial trunnions extending in opposite directions at right angles to the lengthwise direction of the socket, each trunnion having a pair of diametrically opposite recesses and a journal member constituting a second part of the mounting, the journal member having two side portions, a journal in each side portion for one of the trunnions, and stop means in operative association with the recesses in the trunnions, with play between the stop means and the respective recesses, to provide two positions of rest for the trunnion block member, whereby provision is made for limited angular movement of the trunnion block member and a pick secured in its socketed position with its operative end protruding beyond the side portions of the journal member.

2. A pick and pick-mounting as in claim 1, wherein the central portion of the trunnion block member has the circular section of bar material from which the trunnions are turned.

3. A pick and pick-mounting as in claim 1, wherein the central portion of the trunnion block member has the rectangular section of bar material from which the trunnions are turned.

4. A pick and pick mounting combination as in claim 1, wherein the trunnions rotate in bearing bushes in the journals.

5. A pick and pick-mounting combination for use in a mineral mining machine comprising a pick, a head on the pick, two oppositely directed cutting faces on the head, a pick shank having a transverse hole in a direction parallel to the face widths, a trunnion block member constituting one part of the mounting and having a central portion of circular section with a transverse socket to receive the pick shank, the trunnion block member having a hole intersected by the socket to register with the hole in the shank, a pin extending through the registering holes locating and securing the shank in the socket, the block member having coaxial trunnions extending in opposite directions at right angles to the lengthwise direction of the socket, each trunnion having a pair of diametrically opposite recesses and a journal member constituting a second part of the mounting, the journal member having two side portions, an integral bottom web and integral webs intermediate the top and bottom of the member, inner faces on the intermediate webs of arcuate form to conform to the surface of the central section of the trunnion block member, a journal in each side portion for one of the trunnions, and stop means in operative association with the recesses on the trunnions, with play between the stop means and the respective recesses, to provide two positions of rest for the trunnion block member, whereby provision is made for limited angular movement of the trunnion block member and a pick secured in its socketed position with its operative end protruding beyond the side portions of the journal member.

6. A pick and pick-mounting combination for use in a mineral mining machine comprising a pick, a head on the pick, two oppositely directed cutting faces on the head,

a pick shank having a transverse hole in a direction parallel to the face widths, a trunnion block member constituting one part of the mounting and having a central portion of rectangular section with a transverse socket to receive the pick shank, the trunnion :block member having a hole intersected by the socket to register with the hole in the shank, a pin extending through the registering holes locating and securing the shank in the socket, the block member having coaxial trunnions extending in opposite directions at right angles to the lengthwise direction of the socket, each trunnion having a pair of diametrically opposite recesses, and a journal member constituting a second part of the mounting, the journal member having two side portions, 21 journal in each side portion for one of the trunnions, a web forming projection at the bottom of each side portion, the two side portions being welded together to secure the two side portions together and form a bottom web.

7. A pick and pick-mounting combination for use in a mineral mining machine comprising a pick, a head on the pick, two oppositely directed cutting faces on the head, a pick shank having a transverse hole in a direction parallel to the face widths, a trunnion block member constituting one part of the mounting and having a central portion with a trnasverse socket to receive the pick shank, the trunnion block member having a hole intersected by the socket to register with the hole in the shank, a pin extending through the registering holes locating and securing the shank in the socket, the block member having coaxial trunnions extending in opposite directions at right angles to the lengthwise direction of the socket, each trunnion having a pair of diametrically opposite recesses and a hole extending between the recesses and a journal member constituting a second part of the mounting, the journal member having two side portions, a journal in each side portion for one of the trunnions, each journal having a pair of diametrically opposite holes, a pin extending through the holes in the journal and the trunnion member, with play between the pin and the recesses, to provide two positions of rest for the trunnion block member, whereby provision is made for limited angular movement of the trunnion block member and a pick secured in its socketed position with its operative end protruding beyond the side portions of the journal member.

8. A pick and pick-mounting as in claim 7, wherein clearance bushes lie in the recesses in the trunnions.

References Cited UNITED STATES PATENTS 2,595,565 5/1952 Buttrick 299-91 2,690,904 10/ 1954 Muschamp et al 299-91 FOREIGN PATENTS 220,350 9/1957 Australia.

ERNEST R. PURSER, Primary Examiner. 

